At Joanns there is anti pill fleece, which is a variation on Blizzard fleece. It's OK.
Malden Mills Polartec or Windpro is harder to find. Here in Portland we have one store that happened to have a little but doesn't always.
Green Acre Designs sells diaper sewing supplies and has Malden Mills Windpro, sold by the inch. I think that's the best deal out there.